Network problem

[guyishai1]

Hello,

I have three computers which connect to a single cable modem through a hub, and I wish to work with them all in the same home network.
The problem is, that the modem gives two of the computers IP configuration (the IPs are DHCP) with the same default gateway, which means they're in the same network, and the third PC gets a different one, and can't join the network.
I tried to restart the modem, or obtain a different IP through "ipconfig/renew" in the command promt, but nothing helped. The modem probably has some kind of memory, and it gives each computer his old IP time after time.

The modem is Motorola SURFboard SB4200i. Maybe someone knows how to enter its configturation and restart its IP memory?

Thanks,
Guy.

 

[amdskip]

You only get 1 IP address from your ISP most likely. You need to get a router which is a switch and router all in one.

 

[dandaman32]

My setup works pretty darn well: I have a SpeedStream 4200 DSL modem, which is DMZ'ed to point to my firewall box, which has a dynamic IP. The firewall box is running Endian Firewall, and it has two network cards. The first card is connected to my DSL modem, and the second is connected via a crossover cable to my router. All my client PCs, plus one server, are behind that router. So my setup looks like:

Internet -> ISP -> DSL modem -> Endian Firewall box --xover cable--> router -> clients

The router and the "green" (internal) network card on the EFW box both have static IPs. This allows the EFW box to forward several ports (e.g. 80 and 22) to the router, which in turn forwards them to my webserver. The result is a nearly bulletproof network (since everything is Linux anyway ) that allows me to run a (very secure) webserver. So if you can spare a couple bucks for another computer (my EFW box is 533MHz, and I got it at a garage sale for $4, it works great as a firewall) and a router, you should be able to run all your computers.

-dandaman32

 

[bsobel]

Originally posted by: amdskip
You only get 1 IP address from your ISP most likely. You need to get a router which is a switch and router all in one.

Should read: Depending on your account you most likely get 1 IP address from you ISP. In your case it sounds like you get two. But none the less, those are public IPs not private. You need a router to replace the hub you setup.

Bill

 

[Xtremist]

If the 3rd IP is something like 169.x.x.x (sorry I can't remember what it is off-hand) then that is one MS assigns sometimes if you have a valid network connection but don't receive an IP when you send out a DHCP request.

One thing you COULD try (I'm assuming the other 2 PC's work fine?) is do an ipconfig/all on one of the working ones, write down all that info. Then go to the 3rd PC that doesn't work and assign all that info statically. Make sure the PC you got the info from is turned off as well at this point. Then see if you can ping the gateway (your cable modem). And just see if it works in general. At any rate, good luck, bsobel's right though, you're going to need a router instead of simple hub/switch to get that many online at the same time (without doing some kind of connection sharing).